Means for ascertaining leakage of pistons of double-acting internal-combustion engines



May 5, 1925. 1,536,115

GT MEANS FOR ASCERTAINING LEAKAGE OF PISTONS OF DOUBLE ACTING INTERNAL COMBUSTION ENGINES Fil d May 7, 1923 ill Patented May 5, 1925 UNITED STATES PATENT OFFICE.

GERARD J O'HAN LUGT, OF

AMSTERDAM, NETHERLANDS, ASSIGNOR TO NEDER- LANDSCHE FABRIEK VAN WERKTUIGEN EN SPOORWEGMATERIEEL, G-ENAAMD WERKSPOOR, OF AMSTERDAM, NETHERLANDS, A COMPANY OF THE NETHER- LANDS.

MEANS FOR ASCER'IAINING LEAKAGE OF PISTONS OF DOUBLE-ACTING INTERNAL- COMBUSTION ENGINES.

, Application filed May 7,

To all whom it may concern:

Be it known that I, GERARD J OHAN LUGT, a subject of the Queen of Holland, residing at Amsterdam, the Netherlands, have in vented certain new and useful Improvements in Means for Ascertaining Leakage of Pistons of Double-Acting Internal-Combustion Engines, of which the following is a specification.

Double acting combustion engines have the disadvantage that leakage of the piston does not at once manifest itself, such as is the case in a single acting combustion motor with open ended cylinder. In a single acting combustion motor leakage of the piston is ordinarily accompanied by considerable noise and with the escape of smoke and sometimes sparks from the cylinder. Owing to the fact that the cylinder of a double acting motor is closed at both ends these phenomena cannot be observed with this type of engine, so that in the long run both the piston and the cylinder may be se riously damaged.

The present invention has for its purpose to render leakage of the piston in a double acting combustion engine perceptible from the outside. With this object in iew the invention consists in the provision in the piston between the piston rings which separate the cylinder ends from one another of a circular groove or a chamber formed as a recess in the piston wall. If now the piston rings at one side or at both sides leak, the escaping gases will collect in said chamher, the pressure in which will depend upon the rate of leakage. The cylinder wall is further provided with an aperture in the path of the said groove or chamber, and the flow of gases through this aperture is governed by a controlled closing member such as a stop valve which, when the chamber in the piston moves past the aperture allows during a very short time the gases in said chamber to escape or the pressure in said chamber to be gauged. Since leakage occursonly during the combustion stroke, the said closing member needs only to be opened during this stroke. The movement of the closing member can for instance be effected 1923. Serial No. 637,069.

by a cam or an eccentric on the cam shaft, or by one of the rods or levers which govern the valves at the upper and lower. cylinder ends. The controlled closing member may be mounted in series with another stop valve which, when closed, permits of the closing member to be inspected while the engine is running.

The annexed drawing illustrates an embodiment of the invention in a somewhat diagrammatic manner. A. piston 2 works in the combustion cylinder 1 and is provided with a circular recess 3 between the piston rings 4 and 5 for sealing the upper and the lower cylinder ends, respectively. Centrally intermediate the cylinder covers are the aperture 6,'the stop valve 7, the valve chest 8, and a second stop valve 12. The moment wherein recess 3 comes opposite the aperture 6 valve 9 is opened by the action of an eccentric 10 on the cam shaft 11. When both stop valves 7 and 12 are open, the gases which have collected in chamber 3 through leakage of the piston rings are free to escape into the atmosphere or into the engine room. Such escape shows that the piston rings leak.

-VVha't I claim is I 1. In double acting internal combustion engines, the combination with the closed cylinder provided with an opening in its wall intermediate its ends and a passage leading therefrom, of a piston having an annular recess intermediate its ends adapted to register with the said opening during the movements of the piston, a closing member situated in the said passage and adapted to govern the escape of gases from the said annular recess through the said opening, and means operated by the engine shaft for automatically controlling the said closing member in tune with the cycle'in the said cylinder.

2. The combination as specified in claim 1, in which the said closing member opens only during the combustion stroke of the piston.

In testimony whereof I afiix my signature.

GERARD J OHAN LUGT. 

